Communication Media

Communication Media:

Guided Media

1. Twisted Pair Cable
2. Co-Axial Cable
3. Optical Fiber Cable

Unguided Media

1. Radio Wave
2. Micro Wave
3. Infrared

Twisted Pair Cable

Advantages : 

      1. Cheaper and far easier for installation
2. Less susceptible to electrical interference caused by nearby equipment or wires.
3. Flexible.
4. STP wire can carry data at a faster speed just because extra shielding.

Disadvantages : 

       1. Noise
 2. Slow Bandwidth than Co-Axial and Fiber  

Co-Axial Cable

Advantages 

• Better Transmission then Twisted pair cable.
• Less attenuation and less noise then Twisted Pair
• Mostly used in Broadband Transmission
• Thick coaxial cable has an extra protective plastic cover that help keep moisture away.

Disadvantages 

• Expensive then Twisted pair
• Cannot mixed with TP cable.
• Thick coaxial is that it does not bend easily and is difficult to install.

Optical Fiber Cable

Advantages:

• Total internal reflection 
• One single mode fiber can replace a metal of time larger and heavier.
• Very High data transmission rate
• Suitable for every environment.

Disadvantages 

• Difficult to install
• Connecting two fiber
• Very expensive  as compared TP and Coaxial.
•  Fiber optic versus metal cable is that it is difficult to make connections to with another Fiber Optic.

Guided Media Connectors:

Fiber Optical Cable Connector

Co-Axial Cable Connector

Twisted Pair Cable Connector

Unguided Media

Infrared

Low frequency infrared waves are used for very short distance communication like TV remote, wireless speakers, automatic doors, hand held devices etc. Infrared signals can propagate within a room but cannot penetrate walls. However, due to such short range, it is considered to be one of the most secure transmission modes.

Advantages :

➨Infrared motion sensors detect motion in daytime and nighttime reliably. 
➨The sensor does not require any contact with the product to be sensed. 
➨It provides good stability over time. 
➨It delivers high reputability. 

Disadvantages:

➨Infrared frequencies are affected by hard objects (e.g. walls, doors) , smoke, dust, fog, sunlight etc. Hence it does not work through walls or doors. 
➨Infrared waves at high power can damage eyes. 
➨In monitor & control application, it can control only one device at one time. Moreover it is difficult to control things which are not in LOS (Line of Sight). It requires line of sight between transmitter and receiver to communicate. 

Radio Wave

Transmission of data using radio frequencies is called radio-wave transmission. We all are familiar with radio channels that broadcast entertainment programs. Radio stations transmit radio waves using transmitters, which are received by the receiver installed in our devices.

Both transmitters and receivers use antennas to radiate or capture radio signals. These radio frequencies can also be used for direct voice communication within the allocated range. This range is usually 10 miles.

Advantages of Radio Wave

• Inexpensive mode of information exchange
• No land needs to be acquired for laying cables
• Installation and maintenance of devices is cheap

Disadvantages of Radio Wave

• Insecure communication medium
• Prone to weather changes like rain, thunderstorms, etc.

Micro Wave

Disadvantages:

1. Line-of-sight will be disrupted if any obstacle, such as new buildings, are in the way.
2. Signal absorption by the atmosphere. Microwaves suffer from attenuation due to atmospheric conditions.
3. Towers are expensive to build.

Advantages: 

• No cables needed
• Multiple channels available
• Wide bandwidth